1. Field of the invention
The present invention relates to an emergency blank shutting off plate for a device for conveying and exchanging pouring tubes tightly applied against the lower fixed face of a reference refractory plate or against the mobile face of a slide-plate at the bottom and of a metal pouring vessel, while being pressed upwards against guide-rails who determine a rectilinear trajectory along which slide the aforesaid pouring tubes; the aforesaid blank plate is actuated by a jack, from the loading position to an operating position in the pouring axis direction and from the operating system towards a retracted position.
The invention is mainly applied in the steel industry for continuous casting installations, in order to ensure the immediate and tight stop of a casting operation in case of emergency.
2. Description of the Prior Art
Thanks to document W092/00822, knowledge is already available as regards a device for conveying and exchanging interchangeable tubes for a vessel pouring metal from its the bottom end in which a retractable blank plane or an attached plate for a replacement tube and that of a replacement are arranged to slide on guide rails which are able to transmit an upward pushing force and to guide the traversing displacement of the plates and of the pouring tubes in parallel with their own axis, this by actuation of a jack, from a loading position to an operational position while following the pouring axis, and from the operational position to a retractable position. The replacement pouring tube attached to a plate bears by a common transverse edge against the plate which carries a pouring tube which has to be re-placed or against a blank shutting off plate and removes the latter from the pouring orifice in order for the exchange of tubes to occur without lifting the vessel.
When considering the possibility of a technical or technological incident, it is imperative that means should be immediately available for urgently shut-ting off the pouring operation. For this purpose, it was foreseen for known conveyance and exchange devices, during the pouring operation, a blank refractory plate that was in readiness and juxtaposed by a common transverse edge against a plate carrying the pouring tube in the operating position along the pouring axis. A few moments prior to replacing the worn tube by a replacement tube, the blank plate was removed and the aforesaid replacement tube was than set in position.
However, retracting the blank plate was a somewhat complicated operation because of the extremely high temperatures prevailing around the pouring axis and of the risk of forgotting to put it again in its place or to lose it in the ingot mould by a wrong move of the operator during his preparation work for loading the replacement tube.